1. Field of the Invention
The present invention relates, in general, to the field of electrical power distribution and control systems. More particularly, the present invention relates to a computer controlled irrigation power control system.
2. Description of the Related Art
Today, a farming operation typically covers a very large land area. Many of today's farming operations are becoming increasingly automated and operated remotely wherever possible. Computers are cropping up more and more in the farmhouse in order to maximize yields and practice precision farming techniques. Similarly, the irrigation requirements for such large areas become more complex. To meet this demand, pivot irrigation systems which may cover a circle on the order of a mile across have become very popular and wide spread throughout the mid-west and western states. Since it may take a farmer or his/her employee in these areas an hour or more to reach a distant field, the ability to remotely monitor and operate irrigation systems operation, including fertilizer applications, in that remote field quickly becomes economically advantageous.
For example, the T16 Ranch in southeast Washington state manages 64 central pivot irrigation systems covering 6700 acres of cultivated land with the help of an automated telemetry networked system coupled to a personal computer at the ranch headquarters. The telemetry system monitors start and stop of each pivot, monitors water pressure, monitors end gun hours, and auxiliary pump operation for addition of chemicals through the system. The computer includes a display of the status of each pivot system. The computer software allows the farmer to remotely start and stop and reverse pivot systems from a central location. Remote data collection stations are also located at the pivot locations which provide data to the computer database on wind speed, rainfall, temperature and water flow. This data may then be easily stored, tabulated and compiled into reports on the operations of the individual pivots or the entire farming operation.
Global positioning system receivers mounted on tractor cabs in conjunction with soil parameter sensors on the cultivators are also used to gather field specific soil condition information and provide input to a central computer database. This information is then used by the farm management software to generate grid maps of the fields and their conditions which can then be stored in a computer database. The farmer can then view these maps and make decisions as to appropriate fertilization and conditioning actions necessary to achieve optimum yields. These same receivers may also be used with appropriate moisture and grain flow sensors mounted on the harvesting equipment to obtain and monitor location specific yield information. This information is then integrated into the mapping database to provide the farmer with field specific information to aid in future decision making. These systems go a long way toward assisting the farmer in achieving efficient farm operations. However, there are a number of limitations on these systems and there are several things that these conventional systems do not do. They do not provide data on actual soil conditions in real time over the growing period.
There is currently no remote mechanism for monitoring the actual conditions in the field during the growing season short of actually installing remote sensors in the field which sense, only at the sensor location, such characteristics as soil moisture, phosphorous, nitrogen and potassium content, etc. Soil conditions are dynamic. They change over the growing season depending on local rainfall, irrigation amounts, number of sun days, fertilizer and chemical applications etc. Therefore there is a continuing need for more accurate and dynamic monitoring systems and remote control systems applied to everyday farming operations and such precision farming operations as are described above.
A number of universities and the US Department of Agriculture currently provide, on commercial radio, general irrigation guidelines to farmers. For example, the information may include year to date rainfall averages in a listening area and current moisture requirements, particular crop aspiration rates and recommendations for various crops as an aid to the farmer in determining how much water is needed this week and next, etc. However, this information is general in nature and does not typically reflect the specific soil conditions in the particular farmers field, only general conditions. This published information is useful and constitutes a database of historical information that can be utilized to predict future needs.
Unfortunately, many farm operators are not sophisticated in interpreting this information for the farmer's and the field's specific requirements. Therefore there is a need for a system that can perform this interpretation automatically and either provide to the farmer site specific requirements based on either actual field measurements or historical data coupled with, if available, current weather data and the farmer specific crop and soil conditions or automatically determine and schedule appropriate irrigation operations automatically in the most cost efficient manner to the farmer or property irrigation manager.
Further, irrigation pumping systems for pivots require a great deal of electrical power. The typical rural electrical coops and power company generating stations are historically geared for supplying electrical power only for local farm yard type equipment and residential requirements. They are not generally equipped to handle the major power surges associated with operation of hundreds of pivot system pumps simultaneously. One solution which is utilized by power companies is to price the power to the farmer according to system supply availability and predicted usage at various rates. The power companies are also interested in levelizing the power demand to minimize the amount of power which must be obtained from outside in order to meet peak demands. Consequently, there is a need for an irrigation control system which integrates the irrigation requirements and needs of the farmer with the economically advantageous power rate periods. In addition, there is a need in the power distribution community to levelize the overall electrical load requirements in order to provide their customers with power in the most economical, yet adequate manner
Therefore there is a need for a complete optimization system and method for irrigation control which takes into account actual weather conditions, actual soil conditions, ongoing actual power system demands, special requirements of the farmer/operator, and prioritizes irrigation system operation in accordance with these needs and predetermined constraints.